There exists a plurality of situations wherein it is desirable to dispense a relatively constant volume of liquid, either continuously or at periodic time intervals. For example, typical applications requiring liquid to be dispensed in a controlled fashion include plant feeding or watering, fertilizing, pet watering, pet medicating, lubricating in general, humidifying and fumigating, air freshening, toilet bowl and drain cleaning, just to name a few.
Expanding on the plant feeding or watering example, it is well known that house plants are a popular way to create a pleasant and healthy environment. With current trends, such as cocooning and the increased awareness about the impacts of living environments on the health of individuals, plants of various sorts are being used increasingly in various situations and environments such as dwellings, work places and entertainment environments to beautify and enrich the appearance of the area.
It is also well known that moisture is essential to sustain plant life. In soil, moisture and oxygen are present generally in an inversely proportionate ratio. Accordingly, as the moisture content of the soil increases, the oxygen level decreases. An imbalance between oxygen and water reduces or may even stop photosynthesis. Hence, the maintenance of a proper moisture/oxygen balance optimizes the photosynthetic process for a given plant and, therefore, a plant's growths, assuming that other essential environmental factors are present.
If, for example, the percentage of soil moisture is reduced, the plant roots must expend additional energy in order to obtain moisture by osmosis. This, in turn, necessarily diminishes the energy that would otherwise be available for growth. A deprivation of oxygen by overwatering similarly reduces the growth process.
Plant roots develop randomly and omni-directionally, but survive in any direction only to the extent that moisture is immediately encountered and assimilable. When aridity is encountered, the most efficient finer root endings quickly atrophy. Accordingly, to achieve optimal growth, the majority of container plants require evenness of moisture with regard to both spatial distribution of the moisture and the mean moisture level overtime.
The conventional method of watering a house plant involves saturating the soil mass. Typically, most house plants will stay 100% moist for a few days after being saturated. Over the following days, the moisture level will most often remain intermediate before becoming semi-arid and then arid. Depending on the attentiveness of the plant owner, this arid condition may continue for a number of additional days, often causing residual damage. Thus, during a typical watering cycle, the plant usually experiences an optimal moisture/oxygen balance during only a small portion of the time.
Furthermore, it is often found that the entire root system is not exposed to an even distribution of moisture. Rather, it usually encounters a concentration of moisture in the lower region of the plant container. This diminishes the size of the root system upon which the remainder of the plant's growth depends.
Optimally, watering should be performed on a regular basis using the correct amount of water at appropriate intervals. This is often not the case. Also, if the plant caretaker is absent for any extended period of time, arrangements must be made for watering. The effort and exactness required for conventionally watering plants has been beyond the ability and focus of many who would otherwise enjoy the proximity and decorative value of plants.
Several methods and devices have been proposed for attempting to provide adequate watering in the absence of a plant caretaker. One of these methods involves moving the plants to a sink or other basin and sitting the latter in a shallow level of water in order to soak the roots continuously for the entire period of absence. This method is however harmful to plants requiring roots to dry out between waterings. Too much water can also lead to molds that can kill the plant. Furthermore, this method is impractical where the plants are either numerous and/or too big.
Relatively complex automatic systems using electro-mechanical timers for actuating a valve at preset intervals for a preset period of time are also known. It is also common to use systems having small apertures or restrictors for dripping water continuously onto the plant. Such systems are typically used in a nursery or a garden where plants are grouped closely together and water can be supplied from a pressurized source. Such systems, however, may prove to be impractical or undesirable for a typical home where plants are spread out or moved randomly. Furthermore, these types of systems are both relatively complex and expensive.
Gravity feeding from elevated reservoirs is sometimes used but this method also includes interconnecting various tubings and is therefore impractical for most watering requirements in an office or a home.
Another method for automatically watering plants involves the use of a wick. A container of water is positioned adjacent to or above the plant and a wetted wick is extended from the container to the plant. Capillary action draws water gradually from the container to the plant. This method, however, suffers from numerous drawbacks. Indeed, while it may provide for a generally continuous flow, the rate of flow varies with the level of water in the container. As the level drops, the flow rate slows accordingly. Furthermore, it is very difficult to customize the flow rate for a given application since the flow rate is directly proportional to the capillary action which, in turn, is directly proportional to the level of water in the feeding container.
Other drawbacks associated with prior automatic liquid dispensing systems using a capillary action include the poor reliability of such systems which are subject to malfunction due to clogging. Also, most prior art systems using capillary action are not well suited for providing irrigation to the plant using liquids having physical properties other than those of water such as liquid fertilizers, growth enhancers and the like.
Furthermore, some prior art systems do not allow for dispensing of liquids for extended periods of time using relatively small and aesthetically pleasing dispensing containers. Also, some prior art devices lend themselves to important water losses through evaporation and other types of water losses through poor design choices.
Still furthermore, some prior art devices suffer from being overly complex and from requiring relatively complex maneuvers on behalf of the intended user. Still furthermore, most prior art devices suffer from being unaesthetic and, hence, defeating the purpose of attempting to improve the overall appearance of an area by providing plants. Accordingly, there exists a need for an improved plant watering device.